Abstract
Spray characteristics of heated ethanol fuel using Local-contact Microwave-heating Injector (LMI) are subject of this investigation. The work is a part of the design and development of LMI for ethanol application. The designed injector used in this study was applied the effects of dielectric heating of microwaves on polarized molecule liquids through a coaxial cable. The tip of the coaxial cable touches fuel directly at an injection hole and the microwaves heat the fuel up. Microwave generator was controlled with an inverter and power source was AC100V, 60Hz. The output power could be altered from 20W to 120W. This investigation was performed on two methods of microwave heating that were continuous and intermittent microwave generations, and the powers of heating were 30W, 40W and 50W. The frequency of the microwaves was 2450MHz±30MHz. This study was used Ethanol fuel (99.5%) at a pressure of 297kPa. The fuel temperature at the nozzle tip was measured by using K-type thermocouple. An image data processing evaluated the atomization by using photographs taken by a high-speed digital video camera (50.000 frames per second, 368 pixels × 195 pixels). From these photographs, an analysis and measurement were performed to obtain results of spray penetration and spray angle, as well as wave velocity and wavelength of the sprays. These results reflect the effect of microwave heating on spray characteristics of ethanol fuel.
Keywords: Local-contact Microwave-heating, Atomization / Fuel Injection, Spray, Alternative Fuel